Shantui SD22. Operation and Maintenance Manual

STRUCTURE & PRINCIPLE | FINAL DRIVE

Figure3-38: The final drive’s mechanism of SD22, SD22E and SD22D

No.

Name

No.

Name

No.

Name

Drive disc

Drive sprocket

Floating oil seal

Bearing support

Sprocket hub

Oil seal cover

Primary driving gear

Driving wheel's nut

Casing body

Primary driven gear

Support

Guard plate

Secondary driving gear

Cover

Half shaft

Secondary driven gear

Floating oil seal

Hub

Oil seal cover

113

WALKING MECHANISM | STRUCTURE & PRINCIPLE

3.10 WALKING MECHANISM

The walking mechanism (See Figure 3-41) mainly consists of the track frame (7), the driving wheel

(4), the idler (1), the track roller (6), the carrier roller (3), as well as the track and the track tension

device, to realize the walking of the bulldozer.

s s s D

Figure 3-41: The walking mechanism of SD22

No.

Name

No.

Name

No.

Name

Idler

Driving wheel

Track frame

Carrier roller

Track

Spring

Track roller

Content

Number and sequence

Model

SD22/F/C/W/H

6 (S. D. S. S. D. S)

SD22E/D

7 (S. D. S. D. S. D. S)

SD22S/R

8 (D. S. D. S. S. S. D. S)

116

STRUCTURE & PRINCIPLE | WALKING MECHANISM

3.10.1 TRACK TENSION DEVICE (SEE FIGURE 3-42)

The role of the tension device is to ensure that the track has sufficient tension, to reduce the shock

jump of track during walking and prevent it from falling off during winding.

Figure 3-42

No.

Name

No.

Name

No.

Name

Seat

Sleeve, Guide

Shaft

Limit pipe

Oil plug

Oil cylinder

Spring

Oil injection nozzle

Piston

Lever

Cover

Tube

117

STRUCTURE & PRINCIPLE | WALKING MECHANISM

3.10.3 TRACK ROLLER (SEE FIGURE 3-44)

It supports the weight of the bulldozer, to prevent the lateral derail of the track. Track roller can have

a single flange and double flange structure. This figure shows a double flange track roller’s structure.

Except for the shape of the track roller’s hub (1), other structures of the single-flange track roller and

the double-flange track roller are the same.

Figure 3-44

No.

Name

No.

Name

No.

Name

Track roller hub

Cover

Shaft

Bushing

Floating oil seal

119

WALKING MECHANISM | STRUCTURE & PRINCIPLE

3.10.4 CARRIER ROLLER (SEE FIGURE 3-45)

It supports the upper track, to prevent the track from dropping too much, and to reduce the track’s

shock-jump during moving as well as void the track from fall slipping off sideways.

Figure 3-45

No.

Name

No.

Name

No.

Name

Bracket

Carrier roller

Floating seal seat

Shaft

Cover

Floating seal seat

Floating oil seal

Nut

120

STRUCTURE & PRINCIPLE | WALKING MECHANISM

3.10.5 TRACK

Track’s role is to support the bulldozer’s weight, to ensure the bulldozer’s traction, to enable it to

have sufficient driving force.

Figure 3-46 is the track assembly of bulldozers SD22, SD22E, and SD22D. Figure 3-47 is the track

assembly of bulldozer SD22S.

Figure 3-46

No.

Name

No.

Name

No.

Name

Ring, Dust

Track link

Track bolt

Fixed pin

Spindle sleeve

Track Nut

Seal ring

Sleeve

Master pin

Track shoe

121

HYDRAULIC SYSTEM | STRUCTURE & PRINCIPLE

3.11 HYDRAULIC SYSTEM

Hydraulic system consists two parts: the work equipment’s hydraulic system and the gearshift steer-

ing hydraulic system.

3.11.1 WORK EQUIPMENT’S HYDRAULIC SYSTEM

Figures 3-49 through 3-52 are the schematics showing the hydraulic principle and structure of bull-

dozers SD22, SD22E, SD22D, and SD22S.

Figures 3-49: Illustration of the hydraulic principle of the bulldozers

(SD22, SD22E and SD22D)

124

HYDRAULIC SYSTEM | STRUCTURE & PRINCIPLE

No.

Name

No.

Name

Hydraulic oil tank

Blade lift valve

Hydraulic pump (SAL080+036)

Shuttle Valve

Oil-replenishing valve (blade-raising

Main overflow valve

end)

Oil-replenishing valve (blade-lowering

Check valve

end)

Ripper lift valve

Quick drop valve

Oil-replenishing safety valve (ripper-

BLADE LIFT CYLINDER

lowering end)

Oil-replenishing valve (ripper-raising

Main overflow valve

end)

RIPPER LIFT CYLINDER

Check valve

Blade tilt valve

Flow control valve

Blade tilt cylinder

Check valve

Hydraulic oil filter

128

HYDRAULIC SYSTEM | STRUCTURE & PRINCIPLE

Work equipment’s hydraulic operating principles (See Figure 3-54)

Figure 3-54

The gear pump sucks out the operating oil from the hydraulic tank (28), and pumps it into the

change valve (12), (13), (14). If various work equipment is not operated, the oil will return to the

hydraulic tank through the change valve (28) and the oil filter (18). If the oil filter is blocked at this

point, the oil will push open the oil filter’s safety valve to return to the hydraulic tank. If you oper-

ate change valves (14) or (13), you can control the blade’s cylinder to raise, lower, keep or float the

blade, as well as control the tilting cylinder to tilt the blade to the left or to the right or to keep the

blade unmoved. Operating the change valve (12) can control the ripper oil cylinder, to realize the rip-

per’s raising, lowering and keeping.

There is an intake check valve (24), (25), (26) before change valve to overcome the possible “nodding

impact” from the circular movement of various working mechanisms.

130

HYDRAULIC SYSTEM | STRUCTURE & PRINCIPLE

The overload valve (9) is provided in order to avoid that the

system pressure from becoming too high due to the exessive

load during the ripping operation.

During operation, if the load is too high, system pressure will

exceed the set pressure of 14Mpa for a short time. In this

case, the main overflow valve (17) is opened, and the operat-

ing oil returns to the oil tank through the overflow valve, to pro-

Figure 3-56

tect the system . The main overflow valve’s structure is shown

in Figure 3-56.

When the external force’s direction is the same as the oil cylin-

der piston’s moving direction, in order to avoid a vacuum from

occurring within the oil cylinder, the oil-replenishing valves (10),

(11), (15), (16) are provided (See Figure 3-52) Oil-replenishing

valve's structure shown in Figure 3-57 and Figure 3-58

Figure 3-57

Figure 3-58

132

STRUCTURE & PRINCIPLE | HYDRAULIC SYSTEM

All the above valves are within the hydraulic tank.

In order to prevent dust from contaminating the operating oil, the operating oil tank is made into a

closed structure (Figure 3-59)

Figure 3-59

No.

Name

No.

Name

Inlet

To blade cylinder bottom (lower)

To ripper cylinder head

To ripper cylinder bottom

To the head of the tilting cylinder (tilt

To the bottom of the tilting cylinder

to the right)

(tilt to the left)

To blade cylinder head (raise)

The pump’s oil intake

133

STRUCTURE & PRINCIPLE | HYDRAULIC SYSTEM

The oil of the rotation servo valve comes from the steering

pump, and the oil returns to the steering case. (See Figure

3-61)

No.

Name

No.

Name

Valve cover

Handle

Valve core

Piston

Oil cylinder

Connecting rod

Figure 3-61

The action output end of the rotation servo valve connects to

the valve stem of the work equipment’s change valve through

the connecting rod, to operate the change valve t change di-

rection. There is a positioning mechanism in the floating posi-

tion.

If lever (6) is operated to let valve core (7) rotate clockwise for

an angle (see Figure 3-62), the passage between A and C will

be opened, the pressure oil will enter the bottom of oil cylinder

(12) to push piston (8) and valve cover (1) to rotate clockwise

Figure 3-62

for an angle too, and the connecting rod (13) will operate the

change valve’s stem to move a distance. As at this point the

rotation of valve cover (1) cuts off the passage between A and

C, piston (8) will stop moving immediately. It can move con-

tinuously only when (6) continues to be operated.

If lever (6) is operated to let valve core (7) rotate clockwise

for an angle (see Figure 3-62), the passage between A and

C will be opened, the pressure oil will enter the oil cylinder to

push piston (8) and valve cover (1) to rotate clockwise for an

angle too, and the connecting rod (13) will operate the change

valve’s stem to move a distance. As at this point the rotation of

valve cover (1) cuts off the passage between A and C, piston

(8) will stop moving immediately. It can move continuously only

when (6) continues to be operated.

Figure 3-63

Figure 3-66 shows a neutral operating condition. At this point,

neither the passage between A and C nor the passage be-

tween B and C is opened, the oil cylinder’s piston does not

move, and the valve cover does not rotate either.

As the operation force to the lever just needs to overcome the

friction between valve cores (7) and (1), and the output force is

provided by the oil cylinder, the operation force is dramatically

reduced.

135

HYDRAULIC SYSTEM | STRUCTURE & PRINCIPLE

Transmission pump is a gear pump (See Figure 3-68). The transmission pump is connected with the

transfer case, to convert the mechanical energy into the hydraulic energy. The transmission pump

sucks the hydraulic oil from the steering case through the strainer (12), and the exhausted oil enters

the pressure-adjusting valve (15) through the fine filter (14). After pressure adjustment, the oil enters

the hydraulic torque converter’s overflow valve (5) (The valve's set pressure is 0.87MPa), and the

overflow oil returns to the steering case. Pressurized oil going through the overflow valve enters the

hydraulic torque converter(9), to let the hydraulic torque converter’s back pressure valve (6) ensure

that the oil in the torque converter has sufficient operating pressure. The oil going through the back

pressure valve, after being cooled by the oil cooler, returns to the lubricating valve (11), to lubricate

the transfer case due to the lubricating valve being pressed. After lubrication, the oil flows to the in-

ner of the torque converter housing; The oil overflow from the lubricating valve again goes to lubri-

cate the transmission case, and after lubrication, the oil flows into the steering case. The oil scaven-

ger pump ensures that the oil within the torque converter’s housing can continuously returns to the

steering case.

Oil inlet

Oil outlet

Figure 3-68

No.

Name

No.

Name

No.

Name

Driving gear

Body, Pump

Driven gear

Front pump cover

Rear pump cover

140

HYDRAULIC SYSTEM | STRUCTURE & PRINCIPLE

Install a control valve on the transmission case (See Figure 3-71)

Figure 3-71

Valve (15) is the pressure-adjusting valve, and the adjusting pressure is 2.5Mpa, to ensure the en-

gagement of all the clutches except for Gear 1. After reaching this pressure, the pressure-adjusting

valve is opened, to supply oil to the torque converter. Valve (16) is the fast return valve. The joint ac-

tion of this valve and the pressure-adjusting valve (15) can ensure that when the transmission case’s

various clutches are activated, they can be smoothly engaged or thoroughly disengaged.

When the transmission case’s control lever is operated, the system’s pressure changes according

to the curve in Figure 3-72. At the moment the transmission case is operated to shift a gear, the

pressure drops suddenly, to have the clutch be thoroughly separated. And then, the pressure slowly

rises, to let the clutch smoothly engage, to avoid shock, and to help increase the service life of the

drive system.

142

STRUCTURE & PRINCIPLE | HYDRAULIC SYSTEM

Valve (17) is the pressure relief valve, provided specifically for the Gear 1clutch, and the pressure at

its exit is 1.25MPa. (i.e. the engagement pressure of the Gear 1 clutch)

Valve (18) is the starting safety valve. It is provided in order to avoid the unexpected accidents when

the engine is started while the gearshift knob is on a gear (Gear I, II, III) to let the vehicle move sud-

denly. the vehicle will only start to move when the gearshift knob is in the NEUTRAL position, and

then is put on a gear.

Valve (19) is the speed valve. It is used to operate the transmission case’s clutches to get different

forward and reverse speeds.

Valve (20) is the direction valve. It is used to operate the transmission case’s first clutch and second

clutch , to let the bulldozer move forward or backward. Valves (15) through (20) return oil into the

steering case.

Pressure

rising time

Gear shift

Engagement

Time

Figure 3-72

143

WORK EQUIPMENT | STRUCTURE & PRINCIPLE

3.12 WORK EQUIPMENT

The work equipment mainly refers to the blade and the ripper, used to perform various operations

of the bulldozer. Bulldozer SD22S only has the straight tilt blade. Bulldozers SD22, SD22E, and

SD22D have three types of blades: straight tilt blade, angle blade, and U-Blade.

3.12.1 STRAIGHT TILT BLADE

The push rod of the straight tilt blade is a box-shaped structure, with a good anti-bending strength, a

good anti-pressure stability and good rigidity. The front end is hinged together with the blade using a

cross connector, and the back end is hinged together with the seat (8) fixed on the track frame.

Under the action of the blade’s oil cylinder, both the push rod and the blade’s head rotate with the

seat (8) as the axle, to realize the blade’s raising and lowering. Changing the length of adjusting

screw (5) can change the cutting angle of the blade. Tilting the oil cylinder (6) can enable the blade

to tilt to left or right in a direction perpendicular to the ground.

After being used for a period of time, the cutting edge (2) can be turned around and used again.

3.12.2 U-BLADE

The structure of the U-Blade is slightly the same as that of the straight tilt blade, the action principle

is completely the same, and the only difference is in the shape of the blade. No detailed description

will be made here.

144

WORK EQUIPMENT | STRUCTURE & PRINCIPLE

3.12.3 ANGLE BLADE

Angle blade’s structure is shown in Figure 3-74.

Figure 3-74

No.

Name

No.

Name

No.

Name

No.

Name

Seat

C-Frame

Lower support

The blade’s

Upper support

Screw

End bit

head

Edge, Cutting

Bolt

Nut

The blade (8) is hinged together with the C-Frame (3) through the upper support (5) and the lower

support (4). The C-Frame (3) is hinged together with the seat (2), which is fixed on the track frame.

The blade’s cylinder lets the C-Frame (including the blade) make the fixed-axis swing with seat (2)

as the axis.

Installing the lower support (4) on the C-Frame’s different seats through the unplug pin (1) can let

the blade have three different work positions, to realize 25° rotation to the left or right.

146

STRUCTURE & PRINCIPLE | WORK EQUIPMENT

3.12.4 RIPPER (SEE FIGURE 3-75)

The ripper can be used in conjunction with the straight tilt blade and the angle blade.

Figure 3-75: Angle blade

No.

Name

No.

Name

No.

Name

No.

Name

Connecting

Bracket

Connecting rod

frame

Cross beam

Tooth

Tooth tip

Guard plate

The ripper is a mechanism with four connecting rods installed behind the frame. The bracket (1),

the connecting rod (2), the connecting frame (3) and the cross beam (8) are all connected through a

hinge, and the four hinging points are the four apexes of a parallelogram. So, no matter how the rip-

per’s cylinder moves, when the tooth tip cuts soil, the best cutting angle can be ensured.

The cross beam (8) has two sets of holes to provide two installation locations. After being used for a

while, the tooth tip (10) can be turned 180° to be installed again, to extend its service life. For hard

soil, you can operate using one tooth in the middle or two teeth on the two ends.

147

ELECTRIC SYSTEM | STRUCTURE & PRINCIPLE

3.13 ELECTRIC SYSTEM

3.13.1 DESCRIPTION OF THE ELECTRIC SYSTEM

The bulldozer’s electric system is mainly used to start the diesel engine, the lamps. It consists of the

starting motor, the silicon rectified generator, the magnetic switch, the voltage stabilizer and two 12V

batteries.

Notes:

1. The advanced magnetic switch and voltage relay are used, to better protect elements such as

the starter and starting switch;

2. The silicon rectified generator is used, together with an IC adjuster;

3. When the starting switch is in the “open” position, the Battery relay can automatically cut off the

power supply, to prevent electric leakage;

4. When installing the connectors of various electric assemblies, be sure to pay attention to their

colors, specifications and locations, and never make a wrong connection.

5. When replacing the battery, product of the same model should be used. If a battery with a small

capacity is used, it may be damaged during the starting process due to overload;

6. Each time the continuous start should not be over 10 seconds. The interval between 2 starts

should be around 2 minutes.

3.13.2 ELECTRIC WIRING CHART

Wire tube A

Battery relay

Horn's switch

Fuse box

Wire tube B

Water temperature sensor

Starting motor and safety relay

Horn

Headlamp

Transmission case’s safety switch

Torque converter oil temperature sensor

Wire tube C

Oil pressure gauge’s lead (connector)

Engine and voltage regulator

Figure 3-76

148

STRUCTURE & PRINCIPLE | ELECTRIC SYSTEM

3.13.3 WIRE CODES

The following wire codes can help to understand circuit diagrams

Example: wire code 70A01

“70” represents the wire’s standard cross-section, as shown in the table below:

Clutch’s

Number

Diameter of

Wire’s outer

number of

each strand

Main application circuit

diameter (mm)

teeth

strands

(mm)

0.5

0.2

2.4

0.75

0.2

2.6

0.2

2.8

Instrument, Lighting, Signal

1.5

0.25

3.1

Instrument, Lighting, Signal, Start

2.5

0.25

3.7

Lighting, Signal

0.3

4.5

Power supply, Start

0.3

5.1

Start, Warm-up, Charge

0.4

6.7

Start, Warm-up, Charge

126

0.4

8.5

Starting circuit

196

0.4

10.6

Starting circuit

360

0.5

15.7

Starting circuit

475

0.5

18.2

Starting circuit

“A” represents circuit or functional group, as shown in the table below:

Circuit or functional

Code

Functional assembly

group

Main circuits for starting, pre-heating, and stopping as well

Starting

as their control circuits, main power cables

Charging

Circuits for charging and charging indication etc.

Lighting by front and rear working lamps, indoor lighting,

Lighting

and lighting of the dashboard

Various meters and alarms, braking, steering, backing, and

Signal, instrument

horn etc.

Bond strap

Various bond straps

Windshield wiper and

Windshield wiper, cigarette lighter, and washer etc.

cigarette lighter

Air conditioner, radio &

Air conditioner, fan, heater, and radio & tape recorder etc.

tape recorder

Automatic control

Oil temperature sensor

“01” represents numbering within the group.

149

STRUCTURE & PRINCIPLE | ELECTRIC SYSTEM

No.

Name

No.

Name

1-10

Fuse

NEUTRAL switch

Hour meter

Solenoid valve

Voltmeter

Generator

Oil temperature gauge

Oil temperature sensor

Engine oil pressure gauge

Pressure sensor

Water temperature gauge

Water/oil sensor

Starting switch

Horn

Alarm unit

Ripper tilt solenoid valve

Horn relay

Rear lamp

Ripper tilt switch

Left front lamp

Battery relay

Right front lamp

Horn's switch

Lamp on the left side

Reversing switch

Lamp on the right side

Relay

Compressor

Switch of front & rear lamps

High and Low Voltage switch

Side lamp switch

Charging indicator

Instrument light switch

Power supply

Starting relay

Neutral signal

Safety relay

Charging indicator

Back-up alarm

Earthing

Torque converter’s oil temperature

Thermostat

indicator

Battery

Engine oil pressure indicator

Starter

Engine water temperature indicator

151

MAINTENNANCE | MAINTENANCE

CHAPTER 4: MAINTENANCE

4.1 MAINTENANCE

PRECAUTIONS:

Properly servicing and maintaining the vehicle is very helpful for extending the vehicle’s service life,

ensuring personal & machine safety, increasing productivity, and improving economic benefits.

Operators and maintenance personnel, apart from reading the related requirements mentioned in

the “safety precautions”, should also observe the following.

• Servicing and maintenance personnel must be very familiar with the machine’s structure, perfor-

mance, assembly & disassembly procedures, technical requirements and precautions etc. before

doing related work. Never act blindly. For a difficult service & maintenance project, if you are not

very sure you can do it, you’d better consult your Shantui distributor. Routine maintenance is usu-

ally performed before the vehicle is started and after work each day. Before maintenance, park

the vehicle on a level ground, lower the blade and ripper, lock the locking mechanisms, and then

go ahead with the maintenance. If maintenance is performed without stopping the engine, it must

be carried out by two persons. One person sits in the cab, and the other person performs the

maintenance. Be careful not to touch the moving parts with your body.

• Prior to maintenance, thoroughly clean, brush or wash the surrounding areas of the parts to be

maintained. Pay special attention to the surrounding areas of the oil injection port, the filter, the

oil nozzle, and the housing cover, and these places must be made very clean, to prevent dust

from entering the oil.

153

Shantui SD22. Operation and Maintenance Manual - 4